# Reasoning about Transactional Isolation Levels with Isolde

arXiv: https://arxiv.org/abs/2604.00159 · HTML: https://mlsanity.com/paper/2604.00159/

## Key facts

- Cited by 1 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 31 Mar 2026.

## Built on by (most cited first, 1 of 1)

- [TOKI: A Bitemporal Operator Algebra for Contradiction Resolution in LLM-Agent Persistent Memory](https://mlsanity.com/paper/2606.06240/) (2026)

## Abstract (arXiv)

Most databases can be configured to operate under isolation levels weaker than serializability. These enforce fewer restrictions on the concurrent access to data and consequently allow for more performant implementations. While formal frameworks for rigorously specifying isolation levels exist, reasoning about the semantic differences between specifications remains notoriously difficult. This paper proposes a tool -- Isolde -- that can automatically generate examples that are allowed by an isolation level but disallowed by another. This simple primitive unlocks a range of useful reasoning tasks, including checking equivalence between definitions, and verifying (by refutation) subtle semantic properties of isolation levels. For example, Isolde allowed us to easily and automatically reproduce a famously elusive result from the literature and to discover a previously unknown bug in the alternative specification of a standard isolation level used in a state-of-the-art isolation checker.